1. Field of the Invention
The invention relates to the field of fruit--or other object--handling machines and methods and in particular to apparatus and methods for separating objects on a conveyor system.
2. Description of the Prior Art
The sorting, grading, separation and handling of objects such as fruit, in particular citrus fruits, on conveyor systems in combination with many different types of apparatus including optically sensing devices is well known. An example of a photo-optical fruit grader assigned to the same assignee as the present invention is described by way of example in U.S. Pat. No. 5,164,795. In many of these fruit handling devices, such as the one example just referenced, it is necessary to rotate the fruit on the conveyor system in order to have the fruit properly optically scanned or otherwise handled.
The typical conveyor systems for moving and spinning the fruit is comprised of a conveyor with rotating spools connected by a chain. The spaces between adjacent spools define a pocket in which the fruit is intended to rest. The fruit, which may be of various sizes and even, from run to run, of various types, varying for example from large grapefruit to small limes or lemons, is loaded from hoppers onto the conveyor system through various means, which may involve spinning the spools, and are caused to be distributed in the pockets between the spools as the conveyor moves forward. In an ideal situation, one item of fruit will be positioned in each pocket between the pair of adjacent spools and will be spinning freely without touching the adjacent fruit in adjacent pockets.
However, because of the random nature of loading as well as the some random variation in the size and shape of the fruit, the ideal situation does not always occur. On occasion when fruit of sufficient size is loaded on the conveyor, adjacent pockets will contain fruit of such large diameters that the two large adjacent fruits will touch each other. The result of their touching can in some instances substantially interfere with or prevent the rotation of the fruit. Failure of adjacent fruit to rotate, may then in turn cause failure of the grading or handling system, so that the fruit is not scanned, is erroneously ejected, falls off the conveyor at an inappropriate place or the system otherwise mishandles the fruit. An example of this first type of misarrangement is diagrammatically shown in FIG. 2.
Secondly, it may also happen on occasion that smaller fruit may stack in the pocket in multiples or trip lets as shown in FIG. 3.
Two or more fruit may stack in a single pocket or a third fruit may be stacked in a pocket defined by the adjacent fruit themselves. The fruit handling device typically is not designed to handle fruit in this arrangement or any other arrangement other than a single item of fruit within in each pocket. Therefore, both the misarrangement of types of fruit as shown in FIGS. 2 and 3 and any other arrangement of fruit which results in any situation other than the ideal case must be detected and automatically dealt with to avoid mishandling.
Therefore, what is needed is some type of method and apparatus whereby misarrangements of fruit on a conveyor system in which the fruit is designed to be spun can be corrected.